关键词: 科尔沁沙地, 荒漠化, 分级

Abstract: According to the TM Satellite Image Map taken in 1996 of Horqin Sandy Land, the area of fourteen banners and countries located in central Horqin Sandy Land is 11.3945 million hm², which includes permanent farmlands 2.8141 million hm², mountain lands 2.502 million hm², grasslands without any desertification 1.0608 million hm², forestlands excluding windbreak network of farmlands 0.61 million hm², water areas 0.3198 million hm², public lands 0.2116 million hm², and desertification lands 3.8762 million hm². Of above-mentioned desertification lands, there are 3.2873 million hm² wind erosion lands, 0.1162 million hm² water erosion lands and 0.4727 million hm² desertification salt-alkali lands. In accordance with the above-mentioned figures, it is obvious that to prevent lands from wind erosion is the main work on prevention and cure of desertification of Horqin Sandy Land. And of the wind erosion lands, moving and semi-moving dunes is 0.9201 million hm², desertification grasslands is 1.4933 million hm², and desertification farmlands is 0.8739 million hm². According to the proportion of desertification land area divided by total land area, the degree of desertification of the above-mentioned fourteen banners and countries can be clustered into three grades: severe desertification land, proportion > 40%, including seven banners; middle desertification land, proportion between 20%~40%, including four banners; light desertification land, proportion < 20%, including three banners. According to the analysis on the evolution of Horqin Sandy Land in ancient and modern time, it can be concluded that the main reason of land desertification is the over reclamation.

Key words: Horqin Sandy Land, desertification, grading